Adsorption of Pb~(2+), Cu~(2+) and Zn~(2+) Ions on to Waste Fluidized Catalytic Cracking (FCC) Catalyst

摘要

Batch adsorption experiments of Pb~(2+), Cu~(2+) and Zn~(2+) ions on to waste fluidized catalytic cracking (FCC) catalyst were performed. The results obtained indicate that adsorption time, temperature and pH were the main factors influencing the adsorptive capacities. The adsorption data for each ion were well described by the Freundlich and Langmuir adsorption models. The mechanisms for the adsorption of Pb~(2+), Cu~(2+) and Zn~(2+) ions on to water FCC catalyst involved ion-exchange adsorption of the three kinds of heavy metallic ions studied or the formation of hydroxo complexes. Under the experimental conditions employed, the removal of Pb~(2+), Cu~(2+) and Zn~(2+) ions attained values of 97.0%, 90.5% and 91.5%, respectively. In addition, dynamic adsorption of the respective ions on to a column of FCC catalyst was investigated together with studies of the regeneration of the adsorbent. The results of such column tests showed that Pb~(2+) ions can be effectively removed from aqueous solutions by waste FCC catalyst in a packed bed. The adsorbent was easily regenerated by the use of a flow of hydrochloric acid through the packed bed under the experimental conditions employed.